The Division of Pediatric Hematology/Oncology, Columbia- Presbyterian Medical Center (Columbia) will continue its participation in the Children's Cancer Study Group of which it has been a member since 1957. The purpose of these studies is to devise optimal management for childhood cancer, and to evaluate the biology of childhood tumors. The group at Columbia together with its major affiliate, the Division of Pediatric Hematology/Oncology at New York University, will enter in studies designed in cooperation with other members of the Children's Cancer Study Group all patients with childhood cancer; it will provide management standardized to group requirements, including all required laboratory investigations and biological sampling, for all patients; it will keep accurate records and transmit them promptly to the Group Headquarters for evaluation. In addition to patient entry, investigators from the group at Columbia will participate in protocol design and strategy of experimental approach, providing the input of their expertise and specific resources. Significant contributions will be made to CCSG studies, particularly in the area of brain tumors and new agent studies. The large number of children with brain tumors operated on both at Columbia and at New York University (two of the most active Pediatric Neurosurgery Centers in the Country) will be an invaluable resource to CCSG. Both institutions have now very active Pediatric Neuro-Oncology services. Research in the area of childhood cancer will be fostered, with an eye to providing research input that could lead to group-wide experimentation. The areas under current investigations include: studies of the N-myc oncogene in childhood tumor; studies of cellular differentiation; studies of brain tumors biology; studies of immunophenotypes of leukemia and studies of the endocrine effects of cancer treatment.